1. Field of the Invention
The present invention relates generally to a nail gun, and more particularly, to a nail gun having a safe firing mechanism.
2. Description of the Related Art
To prevent a nail gun from damage while none of any nails is available in the nail gun and a user still fires the nail gun, the nail gun is usually equipped with a safe firing mechanism.
U.S. Pat. No. 6,966,476 disclosed a nail gun having a safe firing mechanism functioning as detecting a coil of nails by a sensor-like mechanism located near a nose portion. The sensor-like mechanism includes a contact piece for contacting each nail moving toward the nose portion, and a safety member stoppable by the contact piece. The contact piece is located near the nose portion and one end of the nail that the contact piece contacts is located inside the nose portion and close to a firing path. When the contact piece contacts one of the nails, the contact piece pivots to no longer stop the safety member, the user can pull the trigger to fire the nail. And then, when the final nail is pushed to the nose portion to be fired, the contact piece pivots back to stop the safety member again and meanwhile, the user cannot pull the trigger. In other words, the sensor-like mechanism can detect whether it is the final nail to identify that there will be none of any nails in the nail gun; if it is not the final nail, the user can still pull the trigger; if it is the final nail, the user cannot pull the trigger in such a way that the nail gun is protected from damage.
However, in the process of pushing the final nail to the firing path, there is no firm holding, e.g. a wire holding the nails, such that it is subject to inaccurate positioning to disable the sensor-like mechanism from accurately identifying whether there will be none of any nails in the nail gun. Under the circumstances, it frequently happens that some of the nails are still available but cannot be fired, such that the user needs to open the nail gun to remove the jammed nail, thus being inconvenient in operation. Besides, while the nail-driving member moves, it will directly impact the contact piece contacting the nail to impair the contact piece in such a way that the safe firing mechanism may malfunction.